DESCRIPTION: (Applicant?s Description) The Southwest Oncology Group has evolved since its inception in 1956 into an adult multi-disease, multi-modality clinical research organization. This organization has grown to include 31 Full Member Institutions, 27 Community Clinical Oncology Program (CCOP) institutions, including 3 Minority-Based (MB) CCOPs, 4 Pilot Program CCOPs and 1 Pilot Program MBCCOP, 25 Urologic Cooperative Outreach Program (UCOP) institutions, and a network of approximately 1,434 Affiliate Program (AFFIL) investigators at 245 Affiliate institutions. In addition, 13 Group institutions also participate in the CTEP Minority Initiative program, which serves to enhance minority accrual in cancer clinical trials. More than 4,000 investigators, representing all research modalities, are members of the Group and actively participate in the registration of patients to cancer treatment and cancer control and prevention protocols. In addition, the Southwest Oncology Group coordinates two large intergroup chemoprevention trials funded by the Division of Cancer Prevention (DCP), the Prostate Cancer Prevention Trial (PCPT) and the Selenium and Vitamin E Cancer Prevention Trial (SELECT). More than 200 PCPT institutional sites affiliated with the Southwest Oncology Group and two other cooperative groups participate in this trial. Currently, over 200 institutional sites affiliated with the Southwest Oncology Group, 4 other cooperative groups, the Veterans Affair Cooperative Studies Group and the Canadian Urologic Oncology Group have been chosen to participate in the SELECT trial. The Southwest Oncology Group is also committed to representative accrual of women and minority patients and subjects to Group clinical trials. To this end, the Group has developed an extremely active Committee on Women and Special Populations, which serves to evaluate and enhance the accrual of women, minorities and special populations (e.g., elderly) to Group trials, identify and address special concerns regarding women?s health issues in the cooperative group setting, and act as a direct liaison with women?s and minority health groups, such as the Office of Research on Women?s Health (ORWH) and the Office of Research on Minority Health (ORMH). The Southwest Oncology Group has continued to pursue the goals of the National Cancer Institute CCOP and MB-CCOP program through innovative membership and cancer prevention and control programs, extensive training and educational opportunities for the Group membership, and unsurpassed excellence in patient accrual and quality.